二极管泵浦激光器中泵浦光分布对激光器模式影响程度的计算方法

在激光器中，通常泵浦光呈不均匀分布，由此引起介质的增益也相应地出现不均匀分布，导致振荡光通过增益区时其分布发生变化。提出一种计算不均匀的泵浦光分布对于激光器内振荡光模式的影响程度，可以近似获得振荡光对原来场分布偏离的百分比的方法。在此基础上，对准连续运转的三向侧面泵浦激光器进行研究，分析不均匀泵浦光分布对振荡光场影响的规律。结果表明:当泵浦功率增加或谐振腔内损耗增加时，振荡光通过增益区时对原来分布的偏离程度也同时增加，呈单调变化关系;泵浦光不均匀分布对振荡光场的影响，与其沿振荡光轴向上的分布无关，仅仅取决于其在与振荡光垂直方向上的不均匀分布程度。通过计算还获得了此类效应的数量级，在2 000 W泵浦功率条件下，这种影响仅使振荡光偏离理想分布不到4%，而泵浦功率达到6 000 W时这种偏离则高达20%以上。

Quantitative calculation of pump-light's influence degree on mode of oscillating laser

In laser rod, the unevenly distributed pump-light caused the gain function vary over the medium, which could bring changes on the mode of the oscillated laser. A method was developed to estimate the influence degree of the non-uniform pumping light on the laser mode, by which the deviation of the oscillating field from its origin form could be given in terms of percentage. Based on it, a quasi-continuous three directional side pumped laser was discussed, in order to find the feature of the affection that the varying pumping light acted on the oscillating laser. Result shows that the changes of the oscillating mode brought by the pumping light have monotonic relations with the pumping power and the cavity loss, and the influence of pumping light on oscillating field only depends on its variation over vertical section, and is free from the distribution along the propagation direction of the oscillating laser. The magnitude order of the effect is obtained through numerical calculation, which is less than 4% when the pumping power is 2 000 W and is larger than 20% when the pumping power is 6 000 W.